1. Field of the Invention
The invention relates to a loading apparatus particularly adapted for loading ore or "muck" into an ore carrier as used in mines, particularly in underground mines.
2. Prior Art
Many types of ore loading devices are known, some of which use a bucket hinged on a pair of articulated arms, such as in a back hoe, to feed a hopper of an upwardly inclined conveyor which dumps the muck from an upper end thereof into an ore carrier. Such devices are limited in that operation of the articulated arms requires considerable skill on the part of an operator because the back hoe is commonly positioned non-symmetrically relative to the conveyor and for an unskilled operator horizontal drawing of the bucket towards the conveyor is difficult with two hinged arms.
When the back hoe is being retracted and the bucket is approaching the conveyor, a main connector between the arms is extended upwardly. This presents problems in underground mines because, for a back hoe with a reasonable reach, the articulated arms are relatively long which require adequate headroom in the drift or tunnel in which the apparatus is operating. Thus, when an apparatus with a reasonable reach is used, additional headroom in the drift must be provided which requires more headroom excavation than is the usual practice. Also crowding of the arms, ie interference between the arms when retracted, causes problems when designing for optimum back hoe stroke. Futhermore to reduce the work of the back hoe, such loading apparatus require moving at irregular intervals to bring the conveyor as close as is practical to the muck pile, which requires the operator to stop mucking, advance the conveyor, and then to recommence mucking. This is time consuming and can result in considerable loss in productivity, and the irregular movement of the apparatus can result in excessive wear of the power train thereof.
The conveyors of such loading apparatus have belts which are subject to damage and heavy wear which necessitates complete replacement of the belt, or repairing or splicing of the belt "in situ" ie without removal from the apparatus. When a belt is repaired "in situ" usually a mechanical hinge joint is used which commonly results in a relatively unsatisfactory belt repair of short life. Also, whilst being repaired the apparatus is inoperative for several hours and obstructs the work area preventing other loading apparatus from working there. If the apparatus is removed from the work area so that a new conveyor belt can be fitted or so that the belt can be repaired by a permanent vulcanized join, this also results in considerable downtime of that particular apparatus but sometimes a replacement apparatus can operate in the same area. Both methods as used presently are relatively unsatisfactory because of the difficulty of replacement of the conveyor belt itself. Thus a conveyor assembly that could easily be serviced as a unit itself without making "in situ" repairs of the belt or requiring removal of the machine from the area would be of advantage.